When the Tube Speaks First: Pseudoxanthomatous Salpingitis Providing a Clue to Underlying Endometriosis

Pseudoxanthomatous salpingitis (PXS) is a rare, non-specific inflammatory condition of the fallopian tube, characterized by the presence of hemosiderin-laden macrophages within dilated tubal plicae. We report the case of a 40-year-old woman presenting with lower abdominal pain with imaging features suggestive of bilateral hemorrhagic ovarian cysts and salpingitis. Intraoperative findings revealed extensive pelvic adhesions consistent with stage IV endometriosis. Histopathological examination of the salpinges demonstrated characteristic features of PXS, including hyperplastic plicae, inflammatory infiltrate, and iron-positive pigment-laden macrophages. This unexpected finding prompted additional sampling of ovarian cysts, which revealed foci of endometrial glands and stroma, confirming and supporting the clinical diagnosis of ovarian endometriosis. This case highlights the importance of recognizing PXS as a potential histological clue to underlying endometriosis, particularly when classical features are inconspicuous. Awareness of this rare entity can aid in prompting further tissue evaluation, thereby contributing to accurate diagnosis and appropriate clinical management.